The effect of corticosteroids on serum sialyltransferase enzyme activities in the rat.
Previous studies have demonstrated corticosteroid regulation of sialyltransferase (sialyl-T) enzyme activities in a number of different tissues throughout the body. In this study we examined the regulatory effect of corticosteroids on serum enzyme activity in the rat. The total serum sialyl-T activity was not affected by a decrease in corticosteroid levels following adrenalectomy. However, while there was a significant increase in enzyme activity following dexamethasone treatment, aldosterone had no effect on this parameter. Subsequent examination of individual sialyl-T enzymes demonstrated a slight decrease in alpha2,6 sialyl-T activity following adrenalectomy which was restored to basal levels following dexamethasone treatment. The activity of the alpha2,3 sialyl-T enzyme was not affected by adrenalectomy or dexamethasone treatment, but was stimulated significantly by aldosterone. In general, the levels of serum sialoglycoproteins mirrored well the activities of the appropriate sialyl-T enzymes. These results demonstrate that serum sialyltransferase activity in the rat is under the influence of circulating corticosteroids.
Maguire
T M
TM
Dept. of Pharmacology and Clinical Pharmacology, University of Dundee, Ninewells Hospital Medical School, UK.
Coughlan
C M
CM
Seckl
J R
JR
Breen
K C
KC
D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000315:Adrenalectomy; D000450:Aldosterone / Q000494:pharmacology; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D037102:Lectins / Q000378:metabolism; D051381:Rats; D012799:Sialyltransferases / Q000097:blood* / Q000378:metabolism; D012995:Solubility
D000305:Adrenal Cortex Hormones; D037102:Lectins; D000450:Aldosterone; D003907:Dexamethasone; D012799:Sialyltransferases